hwmon: (pmbus) Fix LINEAR16 data format

LINEAR16 data format is unsigned, not signed. Impact is that affected
attributes report negative values in the upper half of the supported
value range.

Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>

diff --git a/drivers/hwmon/pmbus_core.c b/drivers/hwmon/pmbus_core.c
index 92540c9cd34e73adb75f1cf51d52cef50d0c1549..6474512f49b08c13cd5ec92a3f686b3fdaa2224c 100644 (file)
--- a/drivers/hwmon/pmbus_core.c
+++ b/drivers/hwmon/pmbus_core.c
@@ -359,20 +359,21 @@ static struct pmbus_data *pmbus_update_device(struct device *dev)
 static int pmbus_reg2data_linear(struct pmbus_data *data,
                                 struct pmbus_sensor *sensor)
 {
-       s16 exponent, mantissa;
+       s16 exponent;
+       s32 mantissa;
        long val;
 
-       if (sensor->class == PSC_VOLTAGE_OUT) {
+       if (sensor->class == PSC_VOLTAGE_OUT) { /* LINEAR16 */
                exponent = data->exponent;
-               mantissa = (s16) sensor->data;
-       } else {
+               mantissa = (u16) sensor->data;
+       } else {                                /* LINEAR11 */
                exponent = (sensor->data >> 11) & 0x001f;
                mantissa = sensor->data & 0x07ff;
 
                if (exponent > 0x0f)
                        exponent |= 0xffe0;     /* sign extend exponent */
                if (mantissa > 0x03ff)
-                       mantissa |= 0xf800;     /* sign extend mantissa */
+                       mantissa |= 0xfffff800; /* sign extend mantissa */
        }
 
        val = mantissa;
@@ -454,19 +455,18 @@ static int pmbus_reg2data(struct pmbus_data *data, struct pmbus_sensor *sensor)
 static u16 pmbus_data2reg_linear(struct pmbus_data *data,
                                 enum pmbus_sensor_classes class, long val)
 {
-       s16 exponent = 0, mantissa = 0;
+       s16 exponent = 0, mantissa;
        bool negative = false;
 
        /* simple case */
        if (val == 0)
                return 0;
 
-       if (val < 0) {
-               negative = true;
-               val = -val;
-       }
-
        if (class == PSC_VOLTAGE_OUT) {
+               /* LINEAR16 does not support negative voltages */
+               if (val < 0)
+                       return 0;
+
                /*
                 * For a static exponents, we don't have a choice
                 * but to adjust the value to it.
@@ -476,9 +476,12 @@ static u16 pmbus_data2reg_linear(struct pmbus_data *data,
                else
                        val >>= data->exponent;
                val = DIV_ROUND_CLOSEST(val, 1000);
-               if (val > 0x7fff)
-                       val = 0x7fff;
-               return negative ? -val : val;
+               return val & 0xffff;
+       }
+
+       if (val < 0) {
+               negative = true;
+               val = -val;
        }
 
        /* Power is in uW. Convert to mW before converting. */